Means for varying the velocity of movement of the breech block in automatic guns



Nov. 13, 1945. J. VESELY 2,389,095

MEANS FOR VARYING THE VELOCITY OF MOVEMENT OF THE BREECH BLOCK IN AUTOMATIC GUNS Original Filed March 4, 1942 F /G. 7 F/G. 6 F/G. 8

3oeVQ$Qkj Inventor B WL A Itorney Patented Nov. 13, 1945 MEANS FOR VARYING THE VELOCITY OF MOVEMENT OF THE BREECH BLOCK IN AUTOMATIC GUNS Josef Vesely, Winchmore Hill, London, England Originalapplication March 4, 1942, Serial No. 433.322. Divided and this application July 17, 343, Serial No. 495,099. In Great Britain June 7 Claims.

for engaging the aforesaid one or more transverse projections.

The invention further resides in an automatic gun having embodied therein breech block velocity varying means of the character above speci- March 4, 1942.

The chief object of the invention is to provide a means for varying the velocity of movement of the breech block in an automatic gun in a simple and efiicient manner.

According to one aspect of this invention there is provided for an automatic gun having a reciprocatable breech block means for varying the ve- It will be understood from what has been said above and from what follows that the present invention is concerned only with a resilient bufier device which always remains in the same axial position in relation to the breech block, i. e. which is not moved laterally into or out of the path of the recoiling breech block in order to change the length of the recoil movement of the locity of movement of such breech block, said breech block or its rate of travel during its firing means prising a breech block and a co-operstroke, this adjustment being made in accordance ating assembly which is adapted for insertion in with this invention simply by varying rotationthe gun between the breech block and the normal ally t e pos t on 0 e S d adjustable plate With recoil spring means of the firearm, said assembly respect to the said abutment and breech block including an abutment member for co-operation without changing the axial relationship between with the said recoil spring means, an adjustable the bufier device as a whole and the breech block. plate movable axially and rotationally but not The accompanying drawing shows by way of otherwise with respect to said abutment member, example one embodiment of the invention. and an auxiliary compression spring disposed be- Figures 1 and 2 are side elevations of a part tween said abutment member and said adjustable of a breech block of an automatic gun provided plate and the latter being adapted, by rotation with the velocity-varying means according to the relative to said abutment member, for selective invention in their inoperative and operative adengagement with different internally formed porjusted positions, respectively; tions of the breech block either to space the said Figure 3 is an end elevation showing the inabutment member from the breech block when terior formation of the breech block according to the said auxiliary spring will be operative, or Figures 1 and 2; to place the abutment member in contact with Figures 4 and 5 are longitudinal sectional views the breech block when the auxiliary spring will taken from opposite sides of Figure 3; be inoperative. Figure 6 is a side elevation of the portions of According to another aspect of the invention, the said velocity-vary means adapted to an auxiliary spring is disposed between an ad- Operate with the breech block? h justable plate or disc and an abutment member Figures 7 d are end elevatlons ShOWlhg the and all these elements are adapted to be disposed alternativh posmons P h adlustable plate of in the path of recoil of the breech block, and thefievlce l m 5 40 Flgure 9 1s a partial sectional View of a recoil said plate or d1sc 1s axially movable and rotation- Spring and a breech block accelerating device any adJu.stab1e Elam/{31y to abutment accorfiing to the invention inserted in the breech 1S provtded h one or more transverse block in the position illustrated in Fig. 2. proJectlons on Its penphery. adapted to be The breech block I of an automatic gun is gaged selectively in longitudinal grooves of Chrprovided in its rear part with an axially or longiferent lengths in a recess in the breech block tudinally directed recess in the walls of which whereby the abutment member may either be Set are formed two pairs of circumferentially spaced so that it is spaced from the end of the breech longitudinal grooves g z and 3 3 of different block with the auxiliary spring in operative posilengths as shown in Figures 3, 4 and 5. These ti n, 0 SO th t t Spring is inoperative- Thus grooves accommodate diametrically opposed t e a ry Spring y e r be a d to transverse projections or wings 4 formed on the be operative or so as to be inoperative. periphery of a rotationally adjustable plate or The invention also comprises a breech block disc 5 forming part of the means for varying having longitudinal grooves of different lengths the velocity of movement of the breech block.

The means according to the 1nvent1on further in a recess therein, which grooves are intended consists of a guide pin 9 on one end of which the said plate 5 is fixed, a sleeve 8 slidable on the other end of the pin 9, an abutment member 7 rigid on the sleeve 8, and a compression spring 6, which constitutes the auxiliary spring, disposed between the plate 5 and the abutment member 1 and surrounding the sleeve ii and the pin 9, the arrangement being such that if pressure is exerted on the outer side of the abutment member I, this may slide with the sleeve 8 along the pin 9 so as to compress the spring 6. When this pressure is relieved the spring 6 returns the parts into the position shown in Figure 6.

A recess IE1 is provided in the outer side of the abutment member I for the reception of one end of a recoil rod H which is loaded at its other end by the recoil spring of the gun.

This part of the velocity-varying means is capable of being inserted within the recess in the breech block I in two alternative ways, according to the position of the plate 5.

If the plate is rotated into a position in which the projections l register with the longer grooves 2 in the recess in the breech block (Figure 1), the velocity-varying means is fully inserted into the breech block and the abutment member rests against the end of the breech block so that the reaction of the recoil spring is transmitted through the rod II and the abutment member 1 positively to the breech block I. In this position the velocity-varying means is without efiect upon the velocity of movement of the breech block.

If the plate 5 is rotated so as to bring the projections 4 into register with the shorter grooves 3, the velocity-varying means when at rest projects in part from the end of the breech block, in the manner shown in Figure 2. In this position the action of the spring 5 is added to that of the recoil spring so that an increased velocity of movement of the breech block is obtained.

I claim:

1. In an automatic gun having a reciprocable breech block and a normal recoil spring, the combination of means for varying the velocity of movement of the breech block, said means comprising an abutment member, an adjustable plate provided with at least one peripheral transverse projection, and an auxiliary spring disposed between said abutment member and said adjustable plate and arranged coaxially with both of these elements, said adjustable plate being axially movable and rotationally adjustable with respect to said abutment member, the assembly consisting of the said adjustable plate, auxiliary spring, and abutment member being disposed between the rear end of the breech block and the normal recoil spring of the gun and in the line of recoil of the breech block, and the said breech block being provided with a longitudinal recess, at least two circumierentially spaced longitudinal grooves of different lengths being provided in the wall of the said recess to be selectively engaged by said peripheral transverse projection of said plate, whereby the degree to which the said auxiliary spring is compressed on the recoil of the said breech block can be varied.

2. In an automatic gun having a reciprocable breech block and a normal recoil spring, the combition of means for varying the velocity of movement of the breech block, said means comprising an abutment member provided with an axial guide sleeve, a guide pin axially slidable and rotatable in said guide sleeve, an adjustable plate fixed upon the said guide pin and having a pan of diametrically oppositely disposed transverse peripheral projections, and an auxiliary compression spring mounted around said guide pin and guide sleeve and between the said abutment mem ber and adjustable plate, the assembly consisting of the said adjustable plate, auxiliary spring, and abutment member being disposed between the rear end of the breech block and the normal recoil spring of the gun and in the line of recoil of the breech block and the said breech block being provided at its rear part with a longitudinal recess, the walls of such recess being provided with at least two pairs of diametrically opposed longitudinal grooves, the grooves of one pair being longer than those of the other pair and circumferentially spaced therefrom, and the transverse projections of the said adjustable plate being adapted for engagement in either the longer or the shorter pair of said grooves as desired, whereby the degree to which the said auxiliary spring is compressed on the recoil of the said breech block can be varied.

3. A breech block assembly adapted to be sub- I stituted for the conventional breech block of an automatic fire arm having a recoil spring, said assembly comprising a reciprocable breech block, a member carried by and slidable axially with respect to said breech block, cooperating means on said breech block and slidable member for selectively limiting the forward displacement of said member relative to said breech block to a greater or a smaller distance, an abutment guided for cooperation with said recoil spring on the one hand and with the rear end of said breech block on the other hand, and auxiliary spring means between said slidable member and said abutment.

4. A breech block assembly adapted to be substituted for the conventional breech block of an automatic fire arm having a recoil spring, said assembly comprising a reciprocable breech block provided with a longitudinal recess and at least two'circumferentially spaced longitudinal grooves of difierent lengths in the wall of said recess, an adjustable plate slidable in said recess and having at least one peripheral transverse projection for cooperation with a selected one of said grooves to determine the extent of the axial movement of said plate in said recess, an abutment guided for cooperation with said recoil spring on the one hand and with the rear end of said breech block on the other hand, and an auxiliary spring between said adjustable plate and said abutment.

5. A breech block assembly, as claimed in claim 4, in which said plate is held in coaxial alignment with said abutment and auxiliary spring, and is axially displaceable and rotationally adjustable with respect to said abutment.

6. A breech block assembly, as claimed in claim 4, in which said plate, auxiliary spring and abutment are disposed in axial alignment and guided in the line of reciprocation of said breech block.

7. A breech block assembly adapted to be substituted for the conventional breech block of an automatic fire arm having a recoil spring, said assembly comprising a reciprocable breech block provided at its rear part with a longitudinal recess, the walls of said recess being provided with at least two pairs of diametrically opposed longitudinal grooves, the grooves of one pair being longer than those of the other pair and circumferentially spaced therefrom, an abutment member arranged for cooperation with the rear end of said breech block on the one hand and with said recoil spring on the other hand, said abutment member including an axial guide sleeve, a guide pin axially slidable and rotatable in said guide sleeve, an adjustable plate fixed upon said guide pin and slidably insertable in said recess of said breech block, said plate having a pair of oppositely disposed transverse peripheral projections for engagement in either the longer or the shorter pair of said grooves as desired, and

an auxiliary compression spring mounted around said guide pin and guide sleeve and between said abutment member and adjustable plate, said abutment member, adjustable plate and auxiliary spring being arranged in coaxial alignment and normally guided in the line of reciprocation of said breech block.

JOSEF VESELY. 

